In U.S. Pat. No. 5,621,924 (the disclosure of which is hereby incorporated by reference herein) a vacuum tank construction for use with a vacuum toilet assembly is illustrated that has a number of advantages over the prior art. According to the present invention a modification of the vacuum tank construction in the U.S. Pat. No. 5,621,924 patent is provided that has a number of advantages in certain circumstances. While the vacuum tank according to the present invention functions in primarily the same manner as in the U.S. Pat. No. 5,621,924 patent, the construction according to the invention has a lower profile while retaining the same functionality. The lower profile permits mounting in areas where the vacuum tank in the U.S. Pat. No. 5,621,924 patent is too tall.
Also the vacuum tank construction according to the invention has a different dip tube assembly construction that can be installed through the side of the tank, as opposed to a top portion of the tank in the U.S. Pat. No. 5,621,924 patent.
The dip tube assembly according to the invention has a two piece configuration with O-ring seals between the pieces that provides a close coupling of the tank and pump with a minimum overall length of the tank and pump combination. This minimum overall length permits installation of the vacuum tank where other configurations do not fit, particularly important on boats and recreational vehicles where the vacuum tanks of the invention are designed to be used. Also the dip tube assembly according to the invention has less material than in the U.S. Pat. No. 5,621,924 dip tube, and has better evacuation of the tank and less tendency to plug.
According to one aspect of the present invention there is provided a vacuum tank assembly comprising: A plastic vacuum tank having a substantially hollow interior, and a generally rectangular prism exterior configuration, including top, bottom, front, rear, and side surfaces. A first opening in the front surface. And, a dip tube assembly mounted in the first opening in a position such that sewage in the tank may be readily withdrawn therefrom adjacent the bottom surface thereof, and constructed to readily connect to a vacuum pump.
The assembly preferably further comprises second and third openings defined in the front surface, and desirably the top surface is substantially devoid of openings. Also desirably the tank has no continuous flat surface greater than 80 square inches in area.
In desired operation, the second opening is typically operatively connected to a vacuum switch of conventional construction, and the third opening is operatively connected to a sewage inlet conduit (in turn connected to a vacuum toilet as disclosed in the U.S. Pat. No. 5,621,924 patent). A vacuum pump and outlet conduit are also operatively connected to the dip tube assembly.
In the preferred embodiment the dip tube assembly comprises an adaptor and an evacuator component, the adaptor connecting the evacuator component to an outlet conduit or vacuum pump, and the evacuator component comprising a substantially tubular evacuation portion having a substantially flat open bottom closely overlying the tank bottom surface in the tank open interior. Also preferably the adaptor comprises a mounting flange and a substantially tubular rear portion extending outwardly from the mounting flange, the rear portion having at least one sealing element associated with an exterior surface thereof. Also preferably the evacuator component comprises a substantially tubular connector portion having an interior surface making a substantially air and liquid-tight seal with the sealing element.
In the preferred embodiment the evacuator component connector portion has at least one radially extending locator tab, and the assembly further comprises at least one cut out in the tank front surface adjacent the first opening cooperating with the tab to properly orient the evacuator component in the tank. Also preferably the locator tab has a substantially polygonal cross-section and is removably mounted to the evacuator component. Alternatively the locator tab is integral with the evacuator component connector portion.
According to another aspect of the present invention there is provided a vacuum tank assembly comprising: A vacuum tank having a substantially hollow interior and an exterior having top, bottom, and front surfaces. A first opening in the front surface. A dip tube assembly mounted in the first opening in a position such that sewage in the tank may be readily withdrawn therefrom adjacent the bottom surface thereof, and constructed to readily connect to a vacuum pump. And, wherein the dip tube assembly comprises an adaptor and an evacuator component, the adaptor connecting the evacuator component to an outlet conduit or vacuum pump, and the evacuator component comprising a substantially tubular evacuation portion having a substantially flat open bottom closely overlying the tank bottom surface in the tank open interior.
The details of the dip tube assembly are preferably as described above.
According to another aspect of the present invention there is provided a dip tube assembly per se comprising: An adaptor and an evacuator component, the adaptor connecting the evacuator component to an outlet conduit or vacuum pump, and the evacuator component comprising a substantially tubular evacuation portion having a substantially flat open bottom closely overlying the tank bottom surface in the tank open interior. The adaptor comprising a mounting flange and a substantially tubular rear portion extending outwardly from the mounting flange, the rear portion having at least one sealing element associated with an exterior surface thereof; and the evacuator component comprising a substantially tubular connector portion having an interior surface making a substantially air and liquid-tight seal with the sealing element. And, at least one locator tab extending radially outwardly from the evacuator component connector portion.
It is the primary object of the present invention to provide a low profile vacuum tank having the same or improved functionality as conventional vacuum tanks, and a desirable dip tube assembly for use therewith. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.